Water level maintenance device for swimming pools

ABSTRACT

A device for maintaining the water in a swimming pool at an established level, is disclosed. The subject device involves a water-level tank which has a fluid connection to the swimming pool such that water in both the water-level tank and the swimming pool are at the same level. A double-pole float switch is mounted within the water-level tank to continually sense the water level therein. Whenever the water level is below a selected fill level, the float switch activates an electrical solenoid valve which permits water to be added to the pool. Whenever the water level is above a selected level, the double-pole float switch operates to energize a drain pump which extracts water from the pool until the established water level is attained.

United States Patent 11 1 Schmidt 1 June 19, 1973 [54] WATER LEVELMAINTENANCE DEVICE 2,835,270 /1958 York et a1 137/412 FOR SWIMMING POOLS2,843,144 7/1958 Robinson 6! 2111.... 137/412 3,386,107 6/1968 Wh1ttan,Jr 4/172 17 [76] Inventor: Clinton R. Schmidt, 611 N. Geneva Street,Glendale, Calif. 91206 Primary Exammer -Hemy Art's Attorney-Harold L.Jackson, Stanley R. Jones and [22] Filed: Feb. 7, 1972 Eric T Chung eta]. [2]] Appl. No.: 223,861 ABSTRACT A device for maintaining the waterin a swimming pool [52] 4/172'15 4117117 137,412 at an establishedlevel, is disclosed. The subject device 137/428 involves a water-leveltank which has a fluid connec- [51] Int. Cl E04h 3/16, E04h 3/18 tion tothe Swimming pool such that water in both the [58] Field Of Search4/172, 172.17, 17215; wateplevel tank and the Swimming Pool are at theSame 137/412 428 level. A double-pole float switch is mounted within thewater-level tank to continually sense the water level [56] ReferencesC'ted therein. Whenever the water level is below a selected UNITED STATEPA EN fill level, the float switch activates an electrical sole-2,739,939 3/1956 Leslie 137/428 )1 id va whi h permits water to be addedto the pool. 2,679,260 5/1954 Esselman 137/412 Whenever the water levelis above a selected level, the 3,195,557 7/1965 Young et 137/4l2 Xdouble-pole float switch operates to energize a drain Fever pumpextracts water from the pool until the es 2,707,482 5 1955 Cartar4/172.17 UX tablished water level is attain 2,790,459 4/1957 Thomas137/412 1 2,809,752 10/1957 Leslie 137/428 UX 13 Claims, 2 DrawingFigures 1 M 1a a4 .70 mm? PZ/A/P r7176? f2 a 24 i M0707? BACKGROUND OFTHE INVENTION 1. Field of the Invention This invention generally relatesto devices for controlling the level of water in a swimming pool. Morespecifically, the present invention concerns apparatus for use in acontrol system to maintain the water in a swimming pool at anestablished level.

2. Description of the Prior Art The maintenance of a swimming poolrequires that a generally established range of water levels bemaintained for the water in the pool. Failure to maintain thisestablished water level can result in damage to circulation andfiltration accessories and/or the area surrounding a swimming pool.

Considering first the circulation accessories, a swimming pool istypically equipped with a filtration system including a filter and amotor/pump combination that serves to pump water from the pool throughthe filter for return to the pool. The motor is normally designed tooperate under a load provided by a continuing head of water in the pump.Should this load fail to be present while the motor is operated, seriousand/or permanent damage may in time result. Clearly, such damage iscostly and an inconvenience since the motor must be promptly repairedand/or replaced to avoid the growth of algae.

An abnormally low water level is one of the primary factors contributingto the absence of the water load at the pump. In turn, a decreased waterlevel may be caused by the usual splashing by swimmers or, morecommonly, evaporation. During the summer months, evaporation may requirethat water be added at least once a week. With such a requirement, it isinadvisable to leave a pool unattended for longer periods of time. Thus,vacationing pool owners must obtain the services of someone to maintainthe pool while the owners are away, to avoid damage to the motor.

Damage to the area surrounding the swimming pool can result from theswimming pool overflowing. This may occur as a result of heavy rains.The damage usually results from the chemicals in the pool water harmingsurrounding foliage.

A number of devices have been designed for use in controlling the waterlevel of a swimming pool. However, to the inventors knowledge theseprior art devices have the disadvantage of being affected by activity inthe pool such that when the pool is in use, the water sensing devicemust frequently be disabled to prevent its false operation. Prior artdevices also have the disadvantage of including some mechanical linkagebetween a sensor and a refill device. As a result, the flow of refillwater is reduced to a dribble as the established normal level isapproached. Finally, most prior art control systems are designed to addwater to a pool, while ignoring the problem of overflow water.

It is thus the intention of the present invention to provide a waterlevel maintenance device which operates to automatically maintain thewater level of a swimming pool at an estabilished level or range oflevels wherein water is automatically added to the swimming pool toavoid undesirably low levels and excessive water is automaticallydrained fromthe pool to avoid excessive water levels and/or overflow.

SUMMARY OF THE INVENTION Briefly described, the present inventioninvolves a water-level tank for sensing the water level in a swimmingpool and correcting for abnormally low or high levels by respectivelyadding water to or draining water from the pool. a

More particularly, the subject water level maintenance device includes awater-level tank that is connected via a conduit to receive water fromthe pool such that the level in both the pool and the tank are at thesame level. A float switch is mounted to continually sense the waterlevel in the tank and thus the water level in the swimming pool. Uponthe detection of abnormally low levels, the float switch energizes anelectrical solenoid valve coupled in a refill water line and hencepermits water to be added to the swimming pool to correct for the waterdeficiency. Excessive water levels detected by the float switch causesthe energization of a secondary pump which operates to drain water fromthe pool until the estabilished water level is at tained.

The objects and many attandant advantages of the invention will be morereadily appreciated as the same becomes better understood by referenceto the following detailed description which is to be considered inconnection with the accompanying drawings wherein like reference symbolsdesignate like parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagramillustrating a crosssectional view of a swimming pool accompanied by atypical filtration system and a water level maintenance device connectedin accordance with the present invention.

FIG. 2 is a schematic diagram illustrating a crosssectional view of awater level maintenance device in accordance with the present invention.

Referring to FIG. 1 of the drawings, a swimming pool 10 is customarilyprovided with a. main drain 12 situated at the bottom of the deep end ofthe pool 10 and a skimmer 14 situated along a side of the pool 10.Characteristically, both the main drain I2 and the skimmer 14 operate toprovide water to a filter l6 for retum to the pool 10. A pump 18 drivenby a motor 20 serves to draw the water through the conduits 22 and 24connected respectively to the main drain l2 and the skimmer 14. A valve26 is usually provided to adjust the distributed proportion of waterflow from the main drain 12 and the skimmer 14.

As is well known, the filtration system accompanying a swimming pool maybe operated daily for five or more hours depending on the season andusage. The filtration, and circulation, of the water in the swimmingpool is necessary to keep the water pure and the swim ming poolgenerally clean. Excessive amounts of refuse, such as leaves and/oraccumulated dust, generally must be removed with auxiliary equipmentsuch as a swimming pool vacuum.

The skimmer 14 serves to cause circulation of the surface water of theswimming pool to prevent the accumulation of floating particles that maycontribute to a scum forming at the surface if not drawn off by theskimmer 14. Accordingly, the normal practice is to have both the maindrain l2 and the skimmer 14 in op eration concurrently. The proportionalflow of pool water through the main drain l2 and skimmer 14 is adjustedwith the valve 26 as desired by a pool owner.

As earlier briefly mentioned, abnormally low water levels will result inthe load on the motor 20 being either significantly decreased oreliminated all together. This will normally occur as a result of thewater level dropping to a point that permits air, and hence less water,to be drawn through the skimmer 14. Of course, where the water leveldrops below the level of the weir 28 of the skimmer 14, no water at allwill be drawn through the skimmer 14 and water will fail to be drawn bythe pump 18. The motor 20 consequently will be operated under a no-loadcondition which will quickly cause overheating and consequent damagethereto.

Accordingly, the water level maintenance device of the subject inventionoperates to detect abnormally low water levels and automatically causewater to be added to the pool to maintain the water at an establishednormal level. To this end, a water level tank 30 is buried in reasonableproximity to the pool and connected thereto via a conduit 32 such thatthe water level in the pool 10 and the tank 30 will be the same.

Briefly, the conduit 32 is connected to the swimming pool 10 at the deepend such that activity in the pool causing waves, or other undulation ofthe water surface, will leave the water level in the tank 30 unaffected.The water level in the tank 30 is thus calm despite activity in theswimming pool and hence nned not be disabled while a swimming pool is inuse to prevent false operation. The conduit 32 may be buried and of thenecessary length to permit the tank 30 to be installed in a remotelocation if desired.

The water level in the pool 10 and tank 30 is sensed by a double-polefloat switch 34 which operates to energize a solenoid valve 36 coupledin series with a water main 38 from which water may be added to the pool10. Any conventional electrically operated solenoid valve that isreadily available and well known in the prior art may be used.

The subject water level maintenance device also operates to correct forexcessive water in the pool. This is accomplished by having the floatswitch 34 also detect abnormally high water levels and cause theoperation of a secondary pump 40 which serves to pump water out of thepool 10 and into a drain or sewer line as is convenient. The pump 40 maybe connected to the pool 10 by having a conduit 42 connected to theconduits 22 and 24, as shown. In the alternative, the conduit 42 may bedirectly connected to the pool 10. The secondary pump 40 may be anyconventional centrifugal pump similar to the pump 18 operated by a motor44. The motor 44 may also be any conventional motor available and ofadequate horse power to accomplish the stated purpose.

It is recognized that in some instances such as in the presence of heavyrainfall, water may be added to the pool at a somewhat high rate.Accordingly, the motor 44 and pump 40 should be adequate to preventoverflow and hence distribution of the pool water about the pool area.

The water level maintenance device may now be considered in greaterdetail by reference to FIG. 2. As shown, the water level tank 30includes a main body 46 which is provided with an oversized upperportion 48. A deck flange 50 having an outer diameter sized to besnuggly received within the oversized upper portion 48, is positioned intelescoping relationship with the body 46 of the tank 30. A grate cover52 is used to eliminate the aperture of the deck flange 50. A peripheralshoulder portion 53 is provided to support the grate cover 52. Numerousperforations 54 are provided in the grate cover 52 to permit theatmosphere to readily act upon the water 56 in the tank 30. The floor 55of the tank 30 is provided with a drain 58 which is shaped to receivethe conduit 32 at a mouth 60 thereof.

It is to be understood that the tank body 46 may have any reasonableconfiguration suitable for the described purpose. As an example, thetank body 46 may be cylindrical, etc.

The tank body 46 and deck flange 50 are preferably made of non-corrosivematerial to prevent and/or resist chemical reaction with either thechemicals in the swimming pool water and/or the soil in which the tank30 is embedded.

The oversizing of the upper portion 48, to permit the telescopingadjustment of the flange 50, allows the tank body 46 to be readilyemplaced to have the water level within the pool 10 and the tank 30 thesame and within the operating range of the double pole solenoid switch34. The flange 50 by being telescoping may then be readily, laterleveled with the decking surrounding a pool, and yet have the tank 30include a continuous wall between the deck, or ground level, and thetank floor 55.

Considering the double pole switch 34 in greater detail, any availabledouble pole float switch, such as that marketed by Cutler Hammer, Inc.,would be suitable. characteristically, the switch 34 includes a float 62attached to the end of a supporting rod 64 which is maintained at agenerally vertical position on a switch arm 66. The rod 64 and hence thefloat 62 is adjustable on the arm 66 for the purpose of establishing arange of water levels. To this end, the mid portion of the supportingrod 64 may be threaded to accommodate a pair of lock nuts 68 and 70which operate to secure the rod 64 in a selected position with respectto the arm 66. The end of the switch arm 66 may be notched or aperturedto receive the supporting rod 64.

As an example, the water level shown in FIG. 2 may represent a lowthreshold below which the switch 34 is operated to energize the solenoidvalve 36 by further downward rotation of the arm 66 to make a firstelectrical contact or connection. Excessive water in the swimming pool10, represented by an abnormally high water level as illustrated by thedotted line 72, serves to raise the float 62.

The switch arm 66, as shown in dotted lines, is accordingly rotatedupward to make a second electrical contact and thereby energize themotor 44 to cause the pump 40 to drain water from the pool 10. Uponrestoration of the pool water level to the established range of levels,the first and second electrical contacts are broken and the energizedsolenoid 36 or pump motor 44 are deactivated. The use of the electricalswitch 34 clearly presents the advantage of positive opening and closureof the electrical solenoid 36 and pump motor 44. As earlier mentioned,the prior art mechanical linkages are bulky and restrict the placementof the switch, valve, etc. with respect to each other.

An electrical conduit 74 may be used to direct the necessary electricalcable from the double pole float switch 34 to an appropriate power lineand to the motor 44 and the solenoid 36. A lock nut 76 is adapted tocommunicate with the electric connection 78 of the switch 34 whichextends through the wall of the tank 30.

In that the actual connection of the electric cables between the switch34, the solenoid 36, the motor 44, and a power source may beaccomplished in any well known manner, a detailed description thereofhas been omitted herefrom.

From the foregoing description, it is now clear that the subjectinvention provides a water level maintenance device which is unaffectedby activity in the pool and which operates to automatically maintain thewater level of a swimming pool within an established range of levelssuch that a load is always provided to the pump 18 of the filtrationsystem and overflowing of the swimming pool is prevented.

While a preferred embodiment of the present invention has been describedhereinabove, it is intended that all matter contained in the abovedescription and shown in the accompanying drawings be interpreted asillustrative and not in a limiting sense and that all modifications,constructions and arrangements which fall within the scope and spirit ofthe invention may be made.

What is claimed is:

1. In a water-level control system for swimming pools, a tank forcontaining a portion of the pool water such that the pool water in boththe pool and tank are at the same level, the tank including:

a body formed by a closed upright wall and a floor,

said pool water being contained in said body;

an aperture situated in the floor of said body through which pool wateris permitted to enter said body;

a deck flange positioned to be received by the upper most portion ofsaid closed upright wall of said body, said deck flange serving toextend said upright wall and having a telescoping relationshiptherewith, said deck flange including a hollow cylindrical portionhaving an outer diameter sized to permit said cylindrical portion to bereceived at the end thereof by the uppermost portion of said tank body,said cylindrical portion having a flared peripheral section at the otherend thereof, said flared peripheral section adapted to be positioned atthe surface level of the area in which the tank is located; and

a detector mounted on the upright wall of said body to detect the levelof the pool water in said tank, said detector providing a low electricalconnection whenever the pool water level is below an established lowwater level, and said detector providing a high electrical connectionwhenever the pool water level is above an established high water waterlevel.

2. The apparatus defined by claim 1, said detector including:

water level means for continually sensing the level of said pool waterin the tank body by being maintained at the level of said pool water;

switching means for providing a high or a low electrical connection; and

connector means coupled between said water level means and saidswitching means for operating said switching means to produce a highconnection or a low connection in response to the water levels abovesaid established high water level or below said established low waterlevel, respectively.

3. The apparatus defined by claim 2, said water level means including abuoyant member situated to assume a position corresponding to the levelof the pool water in said tank body, and a supporting rod connected atone end to said buoyant member and having a center portion adapted topermit adjustable attachment to said connector means.

4. The apparatus defined by claim 1, further including a grate forcovering any surface opening provided by said deck flange.

5. The apparatus defined by claim 1, said aperture provided by acylindrical section integrally formed with said floor and having anaxial bore extending for the length thereof and through said floor, saidcylindrical section extending to receive an end of a conduit forpermitting water to flow between said pool and said tank.

6. The apparatus defined by claim 1 further comprising a grate sized tobe centrally positioned within said flared peripheral section of saiddeck flange, said grate covering the central aperture of the flared endof said cylindrical portion of said deck flange.

7. The apparatus defined by claim 6, said detector including:

water level means for continually sensing the level of said pool waterin the tank body by being maintained at the level of said pool water;

switching means for providing a high or a low electrical connection; and

connector means coupled between said water level means and saidswitching means for operating said switching means to produce a highconnection or a low connection in response to the water levels abovesaid established high water level or below said established low waterlevel, respectively.

8. The apparatus defined by claim 7, said water level means including abuoyant member situated to assume a position corresponding to the levelof the pool water in said tank body, and a supporting rod connected atone end to said buoyant member and having a center portion adapted topermit adjustable attachment to said connector means.

9. The apparatus defined by claim 8, said aperture provided by acylindrical section integrally formed with said floor and having anaxial bore extending for the length thereof and through said floor, saidcylindrical section extending to receive an end of a conduit forpermitting water to flow between said pool and said tank.

10. A water level control for swimming pools including the combinationof:

sensing means for continually monitoring the level of water in saidpool, said sensing means capable of being remotely located away fromsaid pool, said sensing means completing first and second electricalconnections in response to the water level being i above an establishedhigh level or below an established low level, respectively, said sensingmeans including:

a secondary tank for containing pool water therein, said tank includinga closed wall and a floor, said conduit means being connected to permitpool water to be supplied to said secondary tank,

detector means positioned in said secondary tank to detect the level ofpool water therein,

flange means for extending the wall of said tank, said flange having aflared peripheral portion suitable for being maintained level with thesurface of the area in which said secondary tank is positioned, saidflange permitting said tank to be open at said surface, and

grate means for covering the tank at said surface, said grate meansadapted to be centrally received by said flange means, said grate meanshaving perforations therethrough for permitting said water in saidsecondary tank to be exposed to the atmosphere;

conduit means for connecting said pool to said sensing means to permitthe flow of water therebetween such that said sensing means isunaffected by waves on the surface of the water in said pool;

draining means responsive to the completion of said first electricalconnection for efi'ecting the removal of water from said pool to havesaid water level adjusted to be no higher than said established highlevel; and

filling means responsive to the completion of said second electricalconnection for permitting the addition of water to said pool to havesaid water level adjusted to be no lower than said established lowlevel.

11. The apparatus defined by claim 10, said draining means including apump operatively connected to remove water from said pool in response tothe presence of said first electrical connection, said water removalcontinuing until at least said established high water level is attained.

12. The apparatus defined by claim 10, said filling means including asolenoid operated valve for permitting the flow of water into said poolin response to the presence of said second electrical connection, saidaddition of water continuing until at least said established low waterlevel is attained.

13. The apparatus defined by claim 12, said detector means including:

water level means for continually sensing the water level in saidsecondary tank, said water level means adapted to follow variations inthe level of the water in said secondary tank;

switching means for completing said first and second electricalconnections; and arm means coupled to said water level means and saidswitching means for operating said switching means to produce said firstelectrical connection in response to water being at a level higher thansaid established high level and said second electrical connection inresponse to water receding below said established low level.

1. In a water-level control system for swimming pools, a tank forcontaining a portion of the pool water such that the pool water in boththe pool and tank are at the same level, the tank including: a bodyformed by a closed upright wall and a floor, said pool water beingcontained in said body; an aperture situated in the floor of said bodythrough which pool water is permitted to enter said body; a deck flangepositioned to be received by the uppermost portion of said closedupright wall of said body, said deck flange serving to extend saidupright wall and having a telescoping relationship therewith, said deckflange including a hollow cylindrical portion having an outer diametersized to permit said cylindrical portion to be received at the endthereof by the uppermost portion of said tank body, said cylindricalportion having a flared peripheral section at the other end thereof,said flared peripheral section adapted to be positioned at the surfacelevel of the area in which the tank is located; and a detector mountedon the upright wall of said body to detect the level of the pool waterin said tank, said detector providing a low electrical connectionwhenever the pool water level is below an established low water level,and said detector providing a high electrical connection whenever thepool water level is above an established high water water level.
 2. Theapparatus defined by claim 1, said detector including: water level meansfor continually sensing the level of said pool water in the tank body bybeing maintained at the level of said pool water; switching means forproviding a high or a low electrical connection; and connector meanscoupled between said water level means and said switching means foroperating said switching means to produce a high connection or a lowconnection in response to the water levels above said established highwater level or below said established low water level, respectively. 3.The apparatus defined by claim 2, said water level means including abuoyant member situated to assume a position corresponding to the levelof the pool water in said tank body, and a supporting rod connected atone end to said buoyant member and having a center portion adapted topermit adjustable attachment to said connector means.
 4. The apparatusdefined by claim 1, further including a grate for covering any surfaceopening provided by said deck flange.
 5. The apparatus defined by claim1, said aperture provided by a cylindrical section integrally formedwith said floor and having an axial bore extending for the lengththereof and through said floor, said cylindrical section extending toreceive an end of a conduit for permitting water to flow between saidpool and said tank.
 6. The apparatus defined by claim 1 furthercomprising a grate sized to be centrally positioned within said flaredperipheral section of said deck flange, said grate covering the centralaperture of the flared end of said cylindrical portion of said deckflange.
 7. The apparatus defined by claim 6, said detector including:water level means for continually sensing the level of said pool waterin the tank body by being maintained at the level of said pool water;switching means for providing a high or a low electrical connection; andconnector means coupled between said water level means and saidswitching means for operating said switching means to produce a highconnection or a low connection in response to the water levels abovesaid established high water level or below said established low waterlevel, respectively.
 8. The apparatus defined by claim 7, said waterlevel means including a buoyant member situated to assume a positioncorresponding to the level of the pool water in said tank body, and asupporting rod connected at one end to said buoyant member and having acenter portion adapted to permit adjustable attachment to said connectormeans.
 9. The apparatus defined by claim 8, said aperture provided by acylindrIcal section integrally formed with said floor and having anaxial bore extending for the length thereof and through said floor, saidcylindrical section extending to receive an end of a conduit forpermitting water to flow between said pool and said tank.
 10. A waterlevel control for swimming pools including the combination of: sensingmeans for continually monitoring the level of water in said pool, saidsensing means capable of being remotely located away from said pool,said sensing means completing first and second electrical connections inresponse to the water level being above an established high level orbelow an established low level, respectively, said sensing meansincluding: a secondary tank for containing pool water therein, said tankincluding a closed wall and a floor, said conduit means being connectedto permit pool water to be supplied to said secondary tank, detectormeans positioned in said secondary tank to detect the level of poolwater therein, flange means for extending the wall of said tank, saidflange having a flared peripheral portion suitable for being maintainedlevel with the surface of the area in which said secondary tank ispositioned, said flange permitting said tank to be open at said surface,and grate means for covering the tank at said surface, said grate meansadapted to be centrally received by said flange means, said grate meanshaving perforations therethrough for permitting said water in saidsecondary tank to be exposed to the atmosphere; conduit means forconnecting said pool to said sensing means to permit the flow of watertherebetween such that said sensing means is unaffected by waves on thesurface of the water in said pool; draining means responsive to thecompletion of said first electrical connection for effecting the removalof water from said pool to have said water level adjusted to be nohigher than said established high level; and filling means responsive tothe completion of said second electrical connection for permitting theaddition of water to said pool to have said water level adjusted to beno lower than said established low level.
 11. The apparatus defined byclaim 10, said draining means including a pump operatively connected toremove water from said pool in response to the presence of said firstelectrical connection, said water removal continuing until at least saidestablished high water level is attained.
 12. The apparatus defined byclaim 10, said filling means including a solenoid operated valve forpermitting the flow of water into said pool in response to the presenceof said second electrical connection, said addition of water continuinguntil at least said established low water level is attained.
 13. Theapparatus defined by claim 12, said detector means including: waterlevel means for continually sensing the water level in said secondarytank, said water level means adapted to follow variations in the levelof the water in said secondary tank; switching means for completing saidfirst and second electrical connections; and arm means coupled to saidwater level means and said switching means for operating said switchingmeans to produce said first electrical connection in response to waterbeing at a level higher than said established high level and said secondelectrical connection in response to water receding below saidestablished low level.